This invention relates to an exercise machine for full body exercise used interactively with a video monitor to create a three-dimensional physical sensation.
Several machines have been developed in recent years that allow for a user to interact with an executing computer program in a physical manner. Many of these machines are essentially interfaces to video games: the user sits in a chair and pushes or pulls on various devices with his arms and legs to control the execution of the game. Two examples of this usage are U.S. Pat. Nos. 4,711,447 and 5,054,771. In both of these systems, the user sits on or in a mechanism that provides a turning and/or tilting action in response to his inputs. These inputs are then in turn monitored by a computer so that "a marker on a computer monitor is computer interactively engagaed with movement of the seat such that swinging motion of the seat causes the marker to selectively move up-and-down and side-to-side on a computer monitor" (U.S. Pat. No. 5,054,771). Although such a system may be sufficient for interactions with two-dimensional game, they lack the fidelity of motion that is needed for the "suspension of disbelief" that is required for motion through a three-dimensional virtual reality (VR) environment, where the feeling of "immersion" is critical.
A commercial machine--the Tectrix VRbike--addresses some of these concerns. The system provides for the actions of riding a recumbent bicycle through a VR landscape. The drawbacks of the Tectrix system are fourfold: Firstly, the turning motion is somewhat limited. To turn, the user pulls on handles that cause the seat to lean. However, since there is no capacity to adjust to the user's weight, then a lightweight user will have a considerably more difficult time in initiating or maintaining a turn than a heavy user.
Secondly, there is little lateral motion to provide the user with the physical sensation of lateral movement that is associated with turning in the real world. Thirdly, the monitor is fixed on the frame. When the user leans through the turn, he must look at the monitor (in the opposite way of the turn), which is counterintuitive and frustrating. Fourthly, the VRbike can only move through an environment that exists in a plane, i.e. the user must remain on the ground in his explorations. This limits significantly the types of environments that the system could potentially explore, for example, the undersea, airborne, or outer space, all require the ability of the user to dive or climb to move through the environment. Additionally, if the mechanism is used for teleoperation of actual, remote systems, the lack of a tilt axis would limit interaction to surface vehicles.